The present invention relates to a noncombustible and smokeless building material, more particularly to a building composite material which has water-insoluble and moisture-absorbing properties, and to a method of manufacturing the same.
In recent years, noncombustible building materials composed mainly of inorganic substances have been developed rapidly so as to meet fire protection needs, and a great number of proposals therefor have been made, most of which suggest methods of combining inorganic substances, in fiber or granular forms, by means of inorganic adhesive material. Particularly, a considerable quantity of sodium silicate has been used as an inorganic adhesive because of its relatively low cost. However, the use of sodium silicate presents disadvantages in the fact that it has a high degree of alkaline concentration in an effluent water solution, and also its strength gradually decreases because of its water-soluble character. In order to eliminate these disadvantages, other improved methods have been proposed, one of which consists of adding a hardening agent or hardener to sodium silicate, and another of which involves a long-time curing process at temperatures of 100.degree. to 200.degree. C. A further method has also been suggested in which such additives as lithium silicate, amine silicate and denatured colloid silica are used. However, all of these conventional methods retain the outstanding problem of water-solubility.
In the light of the above disadvantages and problems, the present invention provides a noncombustible and smokeless building composite material which has both water-insoluble and moisture-absorbing properties, and a method for the manufacture thereof.